A few weeks back, the Washington Post columnist Gene Weingarten published his response to a student who'd emailed, for a college project, to ask how he'd "built his personal brand". "The best way to build a brand," Weingarten deadpanned, "is to take a 3ft length of malleable iron and get one end red-hot. Then apply it vigorously to the buttocks of the instructor who gave you this question. You want a nice, meaty sizzle." For certain professional commentators on the future of journalism, his attack was the battle cry of a curmudgeon who'd failed to grasp the future. "Gene Weingarten has developed an outstanding personal brand as a journalist," retorted the commentator Steve Buttry. "But that brand will not let him write, except scornfully, about branding and journalism." The subsequent dispute lasted days, with most of Weingarten's detractors making the same point: like it or not, he had a brand. Karl Marx, known for his outstanding personal brand as a bearded social critic, would have appreciated this irony of late capitalism: you can't escape the brand. If you try, and succeed, you've simply built a brand as someone who scorns brands.

This would have little significance outside journalism if it weren't for the unstoppable growth of "personal branding" elsewhere: by my estimate, more than 20 books on it have been published in the UK and US in 2011 alone. It's nearly 15 years since the hyperactive management writer Tom Peters announced "the brand called you". But the social networking era has rendered it ubiquitous. Sherry Turkle, in her book Alone Together, is the latest of many thinkers to worry that this self-commodification impoverishes us. Online interactions, she suggests, allow so much stage-management – the core of personal branding – as to preclude intimacy.

The brand-boosters are right that anyone with career success has a brand: they're known for doing something well. "The opposite of 'brand' is 'generic'," writes Buttry, "and no one looking for a job wants to be generic…" But there's a huge unexamined assumption here: that just because you've got a brand, it makes sense to focus on branding, instead of getting on with what you do well. These needn't be mutually exclusive: a little self-promotion's probably essential. But being hyperconscious of how you're presenting yourself is a hindrance, not a help; in everyday life, psychologists will tell you, it's a hallmark of social anxiety disorder. It can also be a waste of time. "Managing and growing a personal brand can be a huge distraction," the self-help author Tim Ferriss – a frenetic self-promoter himself, thus hardly instinctively hostile to branding – said in one interview. Steve Jobs "has a personal brand, but it is Apple's product design that makes it such a valuable company". Jobs's reputation is a by-product.

It's strange, actually, that this pressure to constrain how we present ourselves should be increasing in the age of the web, which offers unprecedented opportunities to benefit professionally from being the unfocused, multifaceted people we really are. Far more than before, if your passions are gherkin-pickling and freelance legal research, there's at least a chance of making both pay. And as personal-branding commentators never quite make clear, pursuing their talents, rather than burnishing their reputations, is how they spend their time, too. It's just their talent is talking about branding. Personally, I prefer gherkins.